1 00:00:00,000 --> 00:00:04,080 Welcome back, my fellow game developers. 2 00:00:04,080 --> 00:00:08,240 In this video, we are taking our game to the next level. 3 00:00:08,235 --> 00:00:10,235 When we run our game. 4 00:00:10,230 --> 00:00:13,470 You'll notice that not only we walk around, 5 00:00:13,470 --> 00:00:15,530 but if we try to leave our map, 6 00:00:15,525 --> 00:00:17,145 there we go. We cannot. 7 00:00:17,145 --> 00:00:19,835 I swear I'm still pressing the achy. 8 00:00:19,830 --> 00:00:23,040 I'm still trying to go down, but it doesn't work. 9 00:00:23,040 --> 00:00:24,540 I'm still trying to go out. 10 00:00:24,540 --> 00:00:28,860 It doesn't work. So we are confined in this little space. 11 00:00:28,855 --> 00:00:32,785 We do that using rigid bodies, using colliders. 12 00:00:32,780 --> 00:00:37,670 And this is really nice because finally we can feel the weight of our game. 13 00:00:37,670 --> 00:00:39,140 So even though we could walk, 14 00:00:39,140 --> 00:00:40,790 we could see we can do anything, 15 00:00:40,790 --> 00:00:43,610 but now we actually have weight to our movement. 16 00:00:43,610 --> 00:00:46,330 We can feel the world around us. 17 00:00:46,325 --> 00:00:48,955 With that said, let's not waste any more time. 18 00:00:48,950 --> 00:00:51,420 And let's get started. 19 00:00:51,424 --> 00:00:53,214 O k. 20 00:00:53,210 --> 00:00:58,760 So currently, when we run our game, 21 00:00:58,760 --> 00:01:01,240 we can move and all that's great. 22 00:01:01,235 --> 00:01:04,915 But as you can see, when we try to hit the wall or something, 23 00:01:04,910 --> 00:01:06,470 we just move bastard. 24 00:01:06,470 --> 00:01:08,990 And it's as if there is nothing in this world. 25 00:01:08,990 --> 00:01:14,680 It feels empty, it feels not real even though we are moving in it. 26 00:01:14,675 --> 00:01:17,495 So how are we going to fix that? 27 00:01:17,495 --> 00:01:20,905 We are going to use something called a collider. 28 00:01:20,900 --> 00:01:24,820 Let me show you what a collider is in the Unity documentation, 29 00:01:24,815 --> 00:01:28,655 as you can see, always referred in Unity documentation, 30 00:01:28,655 --> 00:01:30,385 you can get there through Google. 31 00:01:30,380 --> 00:01:32,540 It's super easy, super effective. 32 00:01:32,539 --> 00:01:36,459 Let's see what we have description based class of colliders. 33 00:01:36,455 --> 00:01:39,055 We have box, sphere, capsule, 34 00:01:39,050 --> 00:01:42,460 a mesh collider, physical materials and rigid bodies. 35 00:01:42,455 --> 00:01:45,145 Something that we will learn in just a bit of 36 00:01:45,140 --> 00:01:47,780 an object with a collider needs to be moved. 37 00:01:47,780 --> 00:01:51,170 During gameplay, you can attach a rigid body component 38 00:01:51,170 --> 00:01:55,580 and we'll just get the rigid body a bit of patients, 39 00:01:55,580 --> 00:01:58,300 you can see all the properties that we can have, 40 00:01:58,295 --> 00:02:01,325 the bounds, the contact offset, the material. 41 00:02:01,325 --> 00:02:05,575 We have public methods such as re-cast closest point. 42 00:02:05,570 --> 00:02:09,160 We have messages which are extremely important and we'll be using 43 00:02:09,155 --> 00:02:13,375 a lot of Trigger Enter on trigger exit on Trigger Stay. 44 00:02:13,370 --> 00:02:18,260 You can read the descriptions right here of what each method, what each property, 45 00:02:18,260 --> 00:02:21,290 what each message means, 46 00:02:21,290 --> 00:02:23,810 what it does, all the inheritance, 47 00:02:23,810 --> 00:02:26,920 what we can use, the compare tag will be very important. 48 00:02:26,915 --> 00:02:29,105 You can see that we have a lot. 49 00:02:29,105 --> 00:02:31,565 You don't have to understand every single one of them. 50 00:02:31,565 --> 00:02:34,865 It's just nice to know that you can, 51 00:02:34,865 --> 00:02:37,595 if you have something in mind to implement, 52 00:02:37,595 --> 00:02:41,425 you can always go into Unit documentations and see if what 53 00:02:41,420 --> 00:02:45,160 you're looking for is available right here. 54 00:02:45,155 --> 00:02:46,885 So with that said, 55 00:02:46,880 --> 00:02:50,020 let's go back in here and let's go ahead and add 56 00:02:50,015 --> 00:02:53,455 a box collider to one of these walls right here. 57 00:02:53,450 --> 00:02:55,150 Let's start with the bottom one. 58 00:02:55,145 --> 00:03:00,425 So the way we do this is we are going to right-click in here. 59 00:03:00,425 --> 00:03:02,135 Or let's go to the background. 60 00:03:02,135 --> 00:03:04,145 Let's add a component in here. 61 00:03:04,145 --> 00:03:07,435 We're going to make it a box collider 2D, 62 00:03:07,430 --> 00:03:11,180 because we are working into this box collider is 3D. 63 00:03:11,180 --> 00:03:12,970 This one is 2D. 64 00:03:12,965 --> 00:03:13,955 We click on it. 65 00:03:13,955 --> 00:03:17,305 You can see that it fills the entire room immediately, 66 00:03:17,300 --> 00:03:18,580 but we don't want that. 67 00:03:18,575 --> 00:03:20,795 We actually want to edit this, 68 00:03:20,790 --> 00:03:22,750 or we can click on the Edit right here. 69 00:03:22,745 --> 00:03:24,605 You can see we can make it a trigger. 70 00:03:24,605 --> 00:03:25,945 We can set an offset, 71 00:03:25,940 --> 00:03:27,280 we can set the size, 72 00:03:27,275 --> 00:03:30,485 so we can make this smaller on the y-axis, 73 00:03:30,485 --> 00:03:34,015 or we can simply click on these three connected dots 74 00:03:34,010 --> 00:03:37,640 right here and just move it manually. 75 00:03:37,640 --> 00:03:40,370 So there you go. 76 00:03:40,370 --> 00:03:45,110 So now we have this collider right here on 77 00:03:45,110 --> 00:03:50,420 the wall or the bottom or whatever you wanna call it, we can unclick. 78 00:03:50,420 --> 00:03:52,820 This will run the game. 79 00:03:52,820 --> 00:03:54,440 And now our player, 80 00:03:54,440 --> 00:03:55,540 when he moves down, 81 00:03:55,535 --> 00:03:57,925 oh, well, what's happening? 82 00:03:57,920 --> 00:04:03,020 The player still hitting the wall and he is moving past. Why is that? 83 00:04:03,020 --> 00:04:06,700 Well, because we don't have a collider on our layer. 84 00:04:06,695 --> 00:04:10,465 So this is going to be your challenge. 85 00:04:10,460 --> 00:04:13,340 Your challenge is to add a collider to the player. 86 00:04:13,340 --> 00:04:15,230 So at a collider, 87 00:04:15,230 --> 00:04:18,470 a capsule, it doesn't have to be a capsule. 88 00:04:18,470 --> 00:04:21,890 It depends on the size and the frame of your player. 89 00:04:21,890 --> 00:04:23,810 The one that true personally got, 90 00:04:23,810 --> 00:04:26,840 or if you're using the same one as I am, 91 00:04:26,840 --> 00:04:32,620 make sure it's only player parent object, not the body. 92 00:04:32,615 --> 00:04:37,885 And change the size of the collider to the appropriate size of your player. 93 00:04:37,880 --> 00:04:39,740 So with these instructions, 94 00:04:39,740 --> 00:04:44,580 pause the video right now and go do the challenge. 95 00:04:44,580 --> 00:04:46,810 Okay, welcome back. 96 00:04:46,810 --> 00:04:49,120 So how did you get on with that? 97 00:04:49,120 --> 00:04:54,150 We are going to add a capsule collider 2D. 98 00:04:54,145 --> 00:04:55,015 There we go. 99 00:04:55,015 --> 00:05:00,015 We have the capsule, capsule shell and not even sure how it's pronounced. 100 00:05:00,010 --> 00:05:01,200 So we click on here. 101 00:05:01,195 --> 00:05:03,795 You can see the little green line in here. 102 00:05:03,790 --> 00:05:06,770 So we are going to take down. 103 00:05:06,774 --> 00:05:13,724 There we go and make it just about the size of our layer. 104 00:05:13,720 --> 00:05:17,260 Now, let's see if that works. 105 00:05:17,260 --> 00:05:19,620 If we run our game. 106 00:05:19,615 --> 00:05:22,695 Now when we go down walk, 107 00:05:22,690 --> 00:05:25,260 we are still moving through the object. 108 00:05:25,255 --> 00:05:26,885 Why is it not working? 109 00:05:26,880 --> 00:05:29,810 I should have probably warned you about this. 110 00:05:29,810 --> 00:05:34,580 Now we are going to add a Rigid Body 2D. 111 00:05:34,580 --> 00:05:36,980 And now when we run the game, 112 00:05:36,980 --> 00:05:40,780 we shall see that we hit the wall. 113 00:05:40,775 --> 00:05:42,995 But I didn't press anything. 114 00:05:42,995 --> 00:05:46,025 If I move up and let go, we fall down. 115 00:05:46,025 --> 00:05:46,975 Why is that? 116 00:05:46,970 --> 00:05:48,460 What is happening? 117 00:05:48,455 --> 00:05:51,175 Well, because when you add a rigid body, 118 00:05:51,170 --> 00:05:53,160 you also add gravity. 119 00:05:53,164 --> 00:05:57,684 Let's delve a little bit deeper into what a rigid body is. 120 00:05:57,680 --> 00:06:03,560 So it control of an object's position through physics simulation. 121 00:06:03,560 --> 00:06:06,940 So when you add a rigid body to a game object, 122 00:06:06,935 --> 00:06:08,855 you add physics to it. 123 00:06:08,855 --> 00:06:16,105 Rigid body object will be pulled downwards by gravity without adding any additional code. 124 00:06:16,100 --> 00:06:20,320 And we can also apply our own forces to them, 125 00:06:20,315 --> 00:06:22,975 which I mean by them, it's the rigid body. 126 00:06:22,970 --> 00:06:28,730 You can also go into unit is documentations and delve deeper into what rigid body is. 127 00:06:28,730 --> 00:06:32,540 And in fact, we are going to need to delve into it. 128 00:06:32,540 --> 00:06:34,190 So I'm going to go in here. 129 00:06:34,190 --> 00:06:37,400 Rigid body unity docs. 130 00:06:37,400 --> 00:06:38,780 There we go. 131 00:06:38,780 --> 00:06:40,070 There we go. 132 00:06:40,070 --> 00:06:42,790 We see the docs Unity 3D. 133 00:06:42,785 --> 00:06:46,495 And you can see the description, the properties, 134 00:06:46,490 --> 00:06:50,020 the public methods and so on and so forth. 135 00:06:50,015 --> 00:06:52,355 So let's go back and again, 136 00:06:52,355 --> 00:06:56,135 we can see right here we can change the mass, the angular drag. 137 00:06:56,134 --> 00:07:00,024 We can change the way the collision is detected, discrete, continuous, 138 00:07:00,020 --> 00:07:02,530 but it takes a bit more processing power, 139 00:07:02,525 --> 00:07:04,405 the sleep mode, the constraints, 140 00:07:04,400 --> 00:07:06,590 we're actually going to use them in just a bit. 141 00:07:06,590 --> 00:07:07,520 You'll see why. 142 00:07:07,520 --> 00:07:11,250 And we can change this from dynamic two kinematic, static. 143 00:07:11,254 --> 00:07:14,214 And each one of those are explained right here. 144 00:07:14,210 --> 00:07:16,330 But the main difference, 145 00:07:16,325 --> 00:07:18,535 whereas it explained somewhere in here, 146 00:07:18,530 --> 00:07:23,150 I'm not sure where you can read about each one to delve deeper into it, 147 00:07:23,150 --> 00:07:27,980 but know that dynamic means to be CAN affected by outside forces. 148 00:07:27,980 --> 00:07:30,290 Kinematic means it doesn't get affected. 149 00:07:30,290 --> 00:07:33,560 And static means is just like a big rock. 150 00:07:33,560 --> 00:07:35,480 It doesn't move at all. 151 00:07:35,480 --> 00:07:37,780 You can see right here the gravity scale. 152 00:07:37,775 --> 00:07:41,215 Let's set it to 0, save that, run the game. 153 00:07:41,210 --> 00:07:44,870 And now you'll notice that we're not fall anymore. 154 00:07:44,870 --> 00:07:46,310 So now when we go down, 155 00:07:46,310 --> 00:07:50,090 you can see that we can no longer go under this. 156 00:07:50,090 --> 00:07:52,720 But what, what, what happened? 157 00:07:52,715 --> 00:07:54,955 And you can see that we move around, 158 00:07:54,950 --> 00:07:56,360 we need to add a box collider. 159 00:07:56,360 --> 00:08:00,090 But what happened in here and what's the, this jittering? 160 00:08:00,094 --> 00:08:03,814 So first thing we'll fix as the flipping things. 161 00:08:03,815 --> 00:08:06,485 So this is because we are rotating. 162 00:08:06,485 --> 00:08:07,765 You can see right here, 163 00:08:07,760 --> 00:08:10,850 it's actually because the physics has calculated that 164 00:08:10,850 --> 00:08:14,020 we should rotate it because of the capsule right here. 165 00:08:14,015 --> 00:08:18,605 So we'll freeze the rotation around the z-axis while Z, 166 00:08:18,605 --> 00:08:26,065 because that show you if we click on the rotate tool up here or simply hit the Iike. 167 00:08:26,060 --> 00:08:28,580 We can see when we rotate, 168 00:08:28,580 --> 00:08:34,640 it's the z-axis that rotates us and we can clearly see it when we go out from 2D, 169 00:08:34,640 --> 00:08:37,370 you can click on this to the right here, we go out. 170 00:08:37,370 --> 00:08:40,240 You'll notice that the z-axis, and you can see it. 171 00:08:40,235 --> 00:08:41,155 There we go. 172 00:08:41,150 --> 00:08:45,070 It's around the z-axis that we are rotating. 173 00:08:45,065 --> 00:08:47,215 So we'll stop the to the, 174 00:08:47,210 --> 00:08:48,970 we'll set this to 0, 175 00:08:48,965 --> 00:08:51,055 will freeze on the Z. 176 00:08:51,050 --> 00:08:53,320 And now when we run our game, 177 00:08:53,315 --> 00:08:57,295 we go down. And there we go. 178 00:08:57,290 --> 00:09:00,350 We no longer flip if we move from left to right, 179 00:09:00,350 --> 00:09:02,930 but we still have this jittering. 180 00:09:02,930 --> 00:09:04,660 And what is this jittering? 181 00:09:04,655 --> 00:09:06,275 Where is it coming from? 182 00:09:06,275 --> 00:09:09,475 Well, it's a matter of code. 183 00:09:09,470 --> 00:09:15,350 We can see right here that we are moving the player using his transform, that position. 184 00:09:15,350 --> 00:09:18,320 So we have two colliding forces. 185 00:09:18,320 --> 00:09:22,900 We have the transformed position trying to go through the swallow, 186 00:09:22,895 --> 00:09:28,295 but we have the physics from the both colliders trying to push the player away. 187 00:09:28,295 --> 00:09:30,775 So this is creating this jittering. 188 00:09:30,770 --> 00:09:32,060 How do we fix this? 189 00:09:32,060 --> 00:09:34,990 Well, we are going to start moving the player, 190 00:09:34,985 --> 00:09:37,105 not using his transform position, 191 00:09:37,100 --> 00:09:40,090 but using his velocity. 192 00:09:40,085 --> 00:09:43,135 And velocity is available on the rigid body. 193 00:09:43,130 --> 00:09:47,120 If you find that somewhere right here, I'm not sure what it is. 194 00:09:47,120 --> 00:09:48,460 Let's see. 195 00:09:48,455 --> 00:09:49,825 Velocity. 196 00:09:49,820 --> 00:09:50,390 There you go. 197 00:09:50,390 --> 00:09:52,190 We can add velocity in here, 198 00:09:52,190 --> 00:09:54,920 angular velocity, the normal velocity. 199 00:09:54,920 --> 00:09:57,010 We can change it right here. 200 00:09:57,005 --> 00:09:58,355 So let's do that. 201 00:09:58,355 --> 00:10:02,245 If we go and you know what, 202 00:10:02,240 --> 00:10:03,550 let's add it up here. 203 00:10:03,545 --> 00:10:06,175 We'll create a serialized field. 204 00:10:06,170 --> 00:10:09,820 This will be a variable of type rigid body 2D, 205 00:10:09,815 --> 00:10:15,395 and we'll just call it the player rigid body. 206 00:10:15,395 --> 00:10:19,165 Save that. Oh, and one more thing you've noticed, 207 00:10:19,160 --> 00:10:20,740 and I forgot to tell you this. 208 00:10:20,735 --> 00:10:23,005 It's the way we name our variable. 209 00:10:23,000 --> 00:10:28,480 The first word should always have the first letter not capitalized, 210 00:10:28,475 --> 00:10:32,065 while all subsequent words will be capitalized. 211 00:10:32,060 --> 00:10:33,290 Why is that? 212 00:10:33,290 --> 00:10:35,110 Let's take an example from here. 213 00:10:35,105 --> 00:10:38,075 You'll notice that player is not capitalized. 214 00:10:38,075 --> 00:10:42,685 Rigid body is by the B for the body is not. 215 00:10:42,680 --> 00:10:44,380 So if we save that, 216 00:10:44,375 --> 00:10:46,475 we'll look in the inspector. 217 00:10:46,475 --> 00:10:48,745 You'll notice right here, the variable, 218 00:10:48,740 --> 00:10:54,980 the way it's written will be player rigid body with rigid body as a single word. 219 00:10:54,980 --> 00:11:00,100 If we go back, we make this be capitalized. 220 00:11:00,095 --> 00:11:01,085 We save that. 221 00:11:01,085 --> 00:11:02,635 We go back in the inspector, 222 00:11:02,630 --> 00:11:08,310 you'll notice that now the B is capitalized and it's a separate word. 223 00:11:08,305 --> 00:11:12,995 So every time we capitalize one of the words, it becomes separate. 224 00:11:12,995 --> 00:11:14,255 But we don't want that. 225 00:11:14,255 --> 00:11:15,865 We want it as a single one. 226 00:11:15,860 --> 00:11:18,730 You can see the same example and the movement speed. 227 00:11:18,725 --> 00:11:20,915 When we go back, there we go. 228 00:11:20,915 --> 00:11:26,795 So we've just created a reference to the rigid body on the player, 229 00:11:26,795 --> 00:11:30,665 but we haven't added it because you can see right now that the player rigid body, 230 00:11:30,665 --> 00:11:33,455 and there's just not how we do that. 231 00:11:33,455 --> 00:11:37,775 We simply click on the rigid body right here and we drag it up. 232 00:11:37,775 --> 00:11:39,235 So now you can see, 233 00:11:39,230 --> 00:11:40,540 as the name suggests, 234 00:11:40,535 --> 00:11:44,935 it's the rigid body on the dune layer. 235 00:11:44,930 --> 00:11:47,990 We save that back in our game. 236 00:11:47,990 --> 00:11:53,480 And here we are going to use instead of the transform position delta and all of that, 237 00:11:53,480 --> 00:11:56,630 I'm just going to comment this outlet on, we'll delete it, 238 00:11:56,630 --> 00:11:59,360 but I just want to have this all in front of 239 00:11:59,360 --> 00:12:02,930 you so you know the process of what's happening. 240 00:12:02,930 --> 00:12:07,180 So now we take the players rigid body, 241 00:12:07,175 --> 00:12:10,015 access the velocity on it. 242 00:12:10,010 --> 00:12:19,030 And it's going to be equal to the movement input times the movement speed. 243 00:12:19,025 --> 00:12:22,375 And because we are using the velocity, 244 00:12:22,370 --> 00:12:25,550 this will not require any Time.deltaTime. 245 00:12:25,550 --> 00:12:27,250 We save that. 246 00:12:27,245 --> 00:12:29,815 We go back in here. 247 00:12:29,810 --> 00:12:32,300 Let's move this guy up a bit. 248 00:12:32,300 --> 00:12:36,230 So now when we run our game, We move around. 249 00:12:36,230 --> 00:12:39,140 And if we try to move through the wall, there you go. 250 00:12:39,140 --> 00:12:42,920 You can see that we no longer have the jittering 251 00:12:42,920 --> 00:12:47,590 because we have the two physics engines working. 252 00:12:47,585 --> 00:12:50,455 Well, not the 2, 1 physics engine working on 253 00:12:50,450 --> 00:12:53,870 the both libraries because of the rigid body. 254 00:12:53,870 --> 00:12:57,880 And finally, we'll just add a couple of more colliders to the background. 255 00:12:57,875 --> 00:13:02,375 So I'm going to add a box collider 2D. 256 00:13:02,375 --> 00:13:05,915 I'm going to make this a bit smaller. 257 00:13:05,915 --> 00:13:12,095 And now it's never recommended that you add multiple box gliders on the same game object, 258 00:13:12,095 --> 00:13:14,505 but for now we'll make an exception. 259 00:13:14,509 --> 00:13:17,079 This will rarely happen. 260 00:13:17,075 --> 00:13:18,665 So there you go. 261 00:13:18,665 --> 00:13:21,155 Let's add a box collider like that. 262 00:13:21,155 --> 00:13:23,575 Let's add another one. 263 00:13:23,570 --> 00:13:26,530 And this one will be to the side. 264 00:13:26,525 --> 00:13:28,075 So we don't go out, 265 00:13:28,070 --> 00:13:30,080 we'll just make it a little bit bigger. 266 00:13:30,080 --> 00:13:34,150 And let's add the last box collider, 267 00:13:34,145 --> 00:13:39,325 and this one will be the one on the other side. 268 00:13:39,320 --> 00:13:42,560 There we go. We save all of that. 269 00:13:42,560 --> 00:13:44,720 We run our game. 270 00:13:44,720 --> 00:13:46,460 And now we walk down. 271 00:13:46,460 --> 00:13:49,130 We can't walk to the left, we can't. 272 00:13:49,130 --> 00:13:51,280 We walked to the right, we can't. 273 00:13:51,275 --> 00:13:52,675 And if we try to move up, 274 00:13:52,670 --> 00:13:55,490 we also can't, but there is a slight problem. 275 00:13:55,490 --> 00:13:59,110 You can see that we still have space in here to walk up to. 276 00:13:59,105 --> 00:14:03,295 So what I'm going to do is I'm going to just make 277 00:14:03,290 --> 00:14:08,410 the players collider a little bit smaller on the top. 278 00:14:08,405 --> 00:14:11,285 So let's just make it around here. 279 00:14:11,285 --> 00:14:19,205 We can even maybe change this from a capsule to something else and making it like that. 280 00:14:19,205 --> 00:14:20,485 Oops. 281 00:14:20,480 --> 00:14:21,410 Where is it? 282 00:14:21,410 --> 00:14:23,620 We change the position, 283 00:14:23,615 --> 00:14:27,835 so we move it on the X. Yep, there we go. 284 00:14:27,830 --> 00:14:29,840 We run our game. 285 00:14:29,840 --> 00:14:33,340 And we can see that we kind of move up. 286 00:14:33,335 --> 00:14:34,885 We still have this bit of space. 287 00:14:34,880 --> 00:14:36,860 This isn't a huge problem. 288 00:14:36,860 --> 00:14:39,590 We can even make B instead of a capsule, 289 00:14:39,590 --> 00:14:42,790 make a box collider or something else. 290 00:14:42,785 --> 00:14:48,515 But you can see that it all works of fine and dandy with that said, 291 00:14:48,515 --> 00:14:50,795 make sure to commit your changes. 292 00:14:50,795 --> 00:14:54,775 And in the next video will be aiming our gun around using 293 00:14:54,770 --> 00:14:59,800 the direction or where our mouse is pointing because currently, 294 00:14:59,795 --> 00:15:02,005 just have this gun is not doing much. 295 00:15:02,000 --> 00:15:04,980 I'll see you in the next one.